Is it possible to deselect element but keep it active?
Based on the comments it seems like the answer to the question is that Active-But-Unselected elements in Edit Mode are not really intended to be used the same way as Active-But-Unselected objects in Object Mode.

Active verts and edges become deactivated when unselected, and unselected faces, while remaining active, become hidden which kind of forces you to "work in the dark".

For the specific use-case I posted in the original question it seems like the cleanest way to achieve that is to use the 3Dcursor as the pivot like sambler and user3800527 mentioned. 

To keep conventions consistent across modes in Blender I wish all elements had a persisting active item that remained visible regardless of selection. It would make learning Blender a lot easier without having to ask so many questions :)